1. Field of the Invention
This invention relates to optical lenses, and, more particularly, to an optical lens that is used for a light emitting diode.
2. Description of Related Art
A light emitting diode (LED) is a semiconductor component that converts a current to a certain wavelength range. An LED, due to its various advantages, such as high light intensity, low working voltage and power consumption, easy compatibility with an integrated circuit, simple driving mechanism, and long lifespan, is widely applied to an illumination field.
In recent years, illumination equipment that employs LEDs is replacing the conventional outdoor illumination equipment such as street light. However, LEDs emit light in a certain direction. Compared with the convention illumination equipment, which emits non-directional light, LEDs have significantly different light distribution. Therefore, LEDs are used as outdoor illumination equipment in a limited manner.
In order for an LED to be used effectively, a lens is designed to cover a packaged LED and calibrate the light emitted from the packaged LED, in order to achieve expected horizontal and vertical beam angles.
How to provide a lens that outputs symmetrical light and has a certain beam angle is one of the most popular development issues in the art.